When traveling in the ocean you never know what you will get. Scientists can try to predict the weather or the amount of animals that will be seen in a particular area but nothing is as valuable as going to the area and recording what you see. For the last couple of days we have been traveling in deep water off the continental shelf of the east coast of the United States. Yesterday, we made a turn toward the edge of the shelf and we were very surprised by what we found. (Check the Ship Tracker to view our path.)

The ocean can best be described as a patchy, dynamic environment. Some days we have traveled for hours and not seen a single animal but on days like yesterday, we saw so many animals our single data recorder was busy all day. Since the start of this cruise we have averaged about 30 sightings a days. Yesterday, we had 30 sightings in the first 30 minutes of observation and ended with over 115 sightings.

Two Common Dolphins

Species ranged from abundant Common Dolphin, to rare and elusive beaked whales. The sighting conditions were so outstanding the Marine Mammal Observers were identifying everything from a small warbler to the second largest whale, a Fin Whale. Large whales, like Sei and Minke Whales, were concentrated in one area, while the dolphins were seen in other areas. We passed over several undersea canyons and cetacean abundance over these canyons was like nothing one of the scientists had ever seen.

Two tools in the ship’s wide array of scientific tools, help scientists document the small animals that the whales and dolphins might be feeding on over the top of the canyons. One is the XBT, or Expendable Bathythermograph, and the second is a VPR, or Video Plankton Recorder. The XBT is launched from the moving ship to document the temperature and water density along the ship’s track. They are inexpensive and record data in real-time, giving accurate and up to date information about the area the animals are most abundant. The VPR is a tool used at night, while the ship moves slowly, to take pictures of the plankton that occurs along our route.

Example of a VPR image

The combination of temperature, depth and photographs of plankton gives scientists a clear picture of the environment that congregates large densities of cetaceans. By understanding the factors that contribute to cetacean population changes, scientists are able to make recommendations to lawmakers about how to protect this natural resource from human impact like bycatch from the fishing industry or ship strikes in commonly trafficked shipping lanes.

Personal Log

I am disappointed that we only have two days left on our trip. I have thoroughly enjoyed my time at sea. Crazy weather this morning of 30 knot winds and 6-8 foot seas will not be a fun memory but thankfully, this evening the weather settled down and we watched a beautiful sunset while playing games on the top deck. I am not sure that I could be a marine mammal observer but I look forward to taking this unique opportunity and turning it into a learning experience for my students.

Since this will be my last post from sea I thought I would leave you with some images of ocean life that was not a marine mammal or seabird. Enjoy.

Today was another great day for sightings. Critter counts include sperm whales, white sided dolphins, a whopping 17 minke whales, a Sei whale, offshore bottle nose dolphins, a finback whale, another pod of pilot whales and 100’s of common dolphins. At one point during my starboard observation shift, both I and my portside counterpart were calling off sightings so rapidly that the recorder was having problems keeping up with us. We both paused for a moment and pulled away from the big eyes to look around and discover that we were surrounded by literally 100’s upon 100’s of common dolphins. The sea was frothing with their activities; some doing aerobatics, others charging, some came to bow-ride of the ship, while other could be seen chasing large fish which were identified as yellow-fin tuna.

Researchers position themselves to rejoin the ship.

In a repeat from several days ago the pilot whale sighting prompted another launch of the zodiac…only this time I got to climb down the Jacob’s ladder and go for a zodiac ride which brought me as close to pilot whale as I could ever hope to be. We were able to procure 5 tissue samples for further genetic study along with an untold number of dorsal fin photographs. (Please see log from August 1st for further explanation of these genetic studies and photos.) My job on the zodiac was to fill out the photography data sheets which record the GPS headings, frame numbers, animal position within pod, approximate size of animal, special markings on the animal, if an attempt to biopsy the whale was made, if the shot resulted in a hit or miss….etc. I was madly recording all this information as cameras were shooting and crossbows were firing and the whole experience whizzed past me. I hope I didn’t forget to record anything!

An ill-fated Northern yellow warbler rests on the deck of thevDELAWARE II

Aside from all the sightings (some of which have become rather common place), and my zodiac ride I really have nothing left to report for the day….except of course that the day flew by. In fact every day passes in a blink…even the foggy ones. I suppose that’s what happens when each day is filled with something new to see and do. Before I sign off for the day I’ll leave you with two more species profiles. One of which may surprise you!

Yellow warbler (Dendroica petechia)

There are approximately 40 subspecies of this widely distributed little bird. This bird, in particular, was most likely from the subspecies aestiva thus making it a ‘Northern’ yellow warbler.

As a true bird-lover I’ve been taking notice and taking note of every new bird I’ve seen while out at sea, and naturally all of the birds I’ve seen lately from black-backed gulls to shearwaters are suppose to be out here in the open ocean searching for fish and bobbing around in the waves while resting. The yellow warbler however is not suppose to be here….and in fact being at sea means certain death for the delicate songbird as its food source is almost non-existent out here and it is ill-equipped to handle a lack of freshwater. The warbler pictured above probably hitched a ride with us following our 24 hour port call in Yarmouth, Nova Scotia. Sad to say that this warbler did in fact perish at sea despite my offerings of fresh water and bread crumbs (I was all out of their primary food which are insects!) A second warbler and a grosbeak did however find the boat as we were coming back into harbor so we hope they were more fortunate then the first stowaway.

Common Dolphins Bow-riding off the DELAWARE II: Note the crisp crisscross markings on the dolphins’ side.

Identification: The yellow warbler is fairly large compared to other warblers and has an exceedingly short set of tail feathers. Both sexes have a yellowish green head and back with yellow underbellies. Females tend to be a bit duller in color while males typically have brown streaks on the cheek and breast. Distribution: The Northern Warbler breeds from Alaska to Newfoundland and Southern Labrador, south to South Carolina and into Northern Georgia, and as far west as the Pacific Coast. It is also found periodically in the American Southwest. Migration: Winters in the Bahamas, Northern Mexico, Peru and the Brazilian Amazon. Diet and Habitat: In its northern and eastern distribution the warblers live in damp habitats surrounding swamps, bogs, marshes, ponds and stream or river banks. They will also feed and nest in woodland areas, meadows, and overgrown pasture lands. In the west and southwest the bird is restricted mainly to riparian habitats. Unfortunately riparian habitat is rapidly decreasing in the Southwest as are the population of yellow warblers within this region. The warbler feeds primarily on insects, but will occasionally eat berries. Listen to its songhere.

Common Dolphin

Until recently both the short-beaked and long-beaked common dolphins were considered to be one species. Although much of the recent research and literature still does not differentiate between short-beaked and long-beaked, they are technically two different species. For the purposes of our survey we also did not distinguish between the two as they are nearly identical in physical appearance.

Short Beaked Common DolphinandLong-beaked Common Dolphin

Identification: Very distinctive crisscross patterning on the sides; yellow/tan patches on the side, dark gray over the topside and pale underside. Light grey patch along the peduncle of the tail.

Max length and weight: 330 pounds and 9 feet. Males are just slightly larger then females

Diet and Feeding: Fish and squid

Migration: No organized or seasonal migration

Distribution: Widely distributed throughout the Atlantic, Pacific, and Indian Oceans as well as the Black and Mediterranean Seas. Special Note: Common Dolphins are especially active and are commonly seen doing aerobatics and bow riding. They are also extremely vocal; to such a degree that their high pitched whistles and clicks may be heard above water.